SQL - Subquery Has 'One Expression' Without Order BY

1	PLAYER1	MARIO
2	PLAYER2	CS
3	PLAYER1	MINECRAFT
4	PLAYER1	DOTA
5	PLAYER1	STARWAR
6	PLAYER2	OXENFREE
NULL	NULL	NULL

--SQL 'ORDER BY' Not Allowed In Subquery

SELECT TOP 30 PERCENT *

FROM

    (SELECT username, COUNT(*) AS C

     FROM plays

     GROUP BY username

     ORDER BY username DESC) T

--Move The 'Order By' To Outside The Subquery

SELECT TOP 30 percent *

FROM

    (SELECT username, COUNT(*) AS c

     FROM plays

     GROUP BY username

     ) T

ORDER BY  c DESC

--Put It All Together

SELECT TOP 30

  username,

  count(*) AS n_plays

FROM plays

GROUP BY username

ORDER BY n_plays DESC;

SELECT * FROM plays

WHERE plays.username

IN (SELECT TOP 30

                username,

                COUNT(*) AS n_plays

        FROM plays

        GROUP BY username

        ORDER BY n_plays DESC

        )

--Output

--(Subquery That Should Return One Column But Is Returning Two)

--PLAYER1       4

--PLAYER2       2

--ERROR - Only one expression can be specified in the select list

--        when the subquery is not introduced with EXISTS.

--OR THE SOLUTION

SELECT * FROM plays

WHERE plays.username

IN (SELECT TOP 30

                username

                --COUNT(*) AS n_plays

        FROM plays

        GROUP BY username

        --ORDER BY n_plays DESC

        )

--PLAYER1  

--PLAYER2

--Alternative

SELECT u.*

FROM plays u JOIN

     (SELECT TOP 30 username, COUNT(*) AS n_plays

      FROM plays p

      GROUP BY p.username

      ORDER BY COUNT(*) DESC

     ) pu

ON pu.username = u.username;